Hollyhocks do not grow from bulbs, though their is a tuberous variety. Hollyhocks are often treated as biennials, but they are actually short-lived perennials with string-like root systems. They are typically grown from seeds (sown outdoors during spring or summer) or from established plants. They really don't like to be transplanted, however, so sowing them directly in the garden works best. Many will even self-sow, depending on your climate. This article will help with growing them: https://www.gardeningknowhow.com/ornamental/flowers/hollyhock/tips-on-hollyhocks-growing-hollyhocks-successfully.htm